Answer:
speed of light simulating traveling at the speed of light. Speed of light, speed at which light waves propagate through different materials. In particular, the value for the speed of light in a vacuum is now defined as exactly 299,792,458 metres per second
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium
E, 63% of the value. I forget the rationale behind it but I learnt that in engineering. 90% confident for that answer.
hey guy
the vibration per second is frequency
then for 20 vibration time taken is 100 second
in 1 second 20/100 vibration took place
it means 0.2 is frequency
for time period , we have
t=1/f
=1/0.2
=5